World Oceans Day reminds us of the major role the oceans have in everyday life. They are the lungs of our planet and a major source of food and medicine and a critical part of the biosphere. Thousands of sea animals are killed each year as a result of marine pollution. Almost one third of reef forming corals, and more than a third of marine mammals are now threatened with extinction. The disappearance of tropical coral reefs also threatens to destroy the livelihoods of half a billion people. Together we can all try to protect our ocean.